My BLOG about my journey into the invisible world of ultraviolet UV photography, simulated bee, butterfly and animal vision photography and the special lenses, filters and lighting needed to make it work - also in HD video + 3D stereo.

Thursday, September 14, 2017

Birds (many of them) have the ability to see UV (ultraviolet) light, which we humans cannot see.

The following graphic illustrates that by comparing our (rather limited) human spectral range to the larger one birds have, including UV (ultraviolet), based on them being tetrachromats (they see 4 colors: UV, Blue, Green, Red approx. 300-700nm), whereas we humans are trichromats (we only see 3 colors: Blue, Green, Red, approx. 400-700nm).

Be reminded: The pink-magenta UV "color" shown here has been chosen to make it better visible for us humans, it is a "false color", as per definition UV light (approx. 300-400nm) has no color!

A flower such as a Rudbeckia fulgida with an underlying UV pattern, invisible to us humans, then looks like this in human vision (left) and simulated bird vision (right):

So how may then birds look like, seen through birds eyes? Possibly like this (it is simulated bird vision on the right):

I have used this to make visible in still photography and videography what birds may seen of a bird protecting device, the FireFly bird diverter, which may bee seen HERE

But how has this been done? Well, in principle using photographic technology, but with a twist:

Normal photography uses (as per today) a digital camera with a built in sensor, a greenish/blue filter stack in front of that sensor, which limits and adjusts its much broader sensitivity range (UV to IR, approx. 300-1000nm) to the human vision range (approx. 400-700nm), using a suitable standard taking lens, made of optical glass. And of course a suitable lightsource is needed, sun being the best, as it provides a useful amount of UV in its light spectrum

Now this type of multispectral photography needs a modified camera (internal filter stack removed and replaced by an UV and visible light transmitting, clear fused silica window), a suitable UV transmitting special quartz-fluorite lens (the UV-Nikkor 105mm being one of only a few ever made ones), and special filters which allow to record UV images (such as the Baader-U UV transmitting, but visible light blocking filter), as well as filters to record the normal visible light (Blue, Green, Red).

The resulting UV and VIS (Blue, Green, Red) images are then suitably combined into one "multispectral image", in our case here the "simulated bird vison" image. [That term "suitably" describes a rather complex mapping process which I will not describe in detail here. NASA uses similar processes to generate their amazing images from their Hubble space telescope or their Earth observation satellites]

Wednesday, September 13, 2017

Today about birds and how to protect them against collision with power lines. Each year millions of birds die, especially when migrating in spring and autumn. The patented FireFly device was invented and manufactured by Hammarprodukter AB to protect them.

The following videos were shot at Kübassaare / Saaremaa Island, Estonia in 2017, as a proof that a carefully designed bird diverting device, such as the patented FireFly (and BirdMark) made by Hammarprodukter AB of Sweden, works efficiently to divert birds and make them change their flight path, hence protecting their lifes.

The following video was shot in June and August 2017 in normal human vision, in simulated bird vision at daylight, but also at dusk / night to show the afterglow effect this FireFly device has, aside from its intense flickering when rotating, which can be seen up to 350-400 meters, which is the visible distance covered in this video. Several overflights were recorded, where birds actively changed their normal flight path.

[best to watch in HD full screen]

Here now a screen shot showing how efficient FireFly was able to divert the flight path of the birds.

Birds (many of them) have the ability to see UV (ultraviolet) light, which we humans cannot see! This grahic here makes this visible by comparing our human spectral range to the larges one birds have, based on them being tetrachromats (they see 4 colors), whereas we humans are trichromats (we see 3 colors).

Be reminded: The pink-magenta UV "color" seen here has been chosen to make it better visible for us humans, it is a "false color", as per definition UV light has no color!

So how may then birds look like, seen through birds eyes? Possible like this (it is simulated bird vision on the right):

The Hammarprodukter FireFly also makes use of this knowledge, to scare birds away from high voltage powerlines, which may harm birds!

Friday, August 4, 2017

Today more shots of a cultivar flower, originating from the USA Prairie, a Black-eyed Susan - Rudbeckia hirta in reflected ultraviolet photography using my "work horse" UV filter, the Baader-U filter as well as in simulated bee and butterfly vision using my XBV filters. All shots were done at f11. Lens was a UV-Nikkor 105mm quartz fluorite lens. Light source was a modified Xenon flash. This was shot using my previously used modified high resolution camera (40/80Mpix).

[click on image to see a larger one]

Human vision:

Reflected UV:

Simulated bee vision:

Simulated butterfly vision:

Quadriptych of human vision, UV, and simulated butterfly and bee vision (left to right, top to bottom):

Quadriptych in detail of human vision, UV, and simulated butterfly and bee vision (left to right, top to bottom):

This flower shows a very prominent UV bullseye pattern, as its petal tips are very UV bright (around 365nm) to about the middle and its center is very UV dark, and all this gets nicely visible also in simulated bee and butterfly vision. I have matched the previously done shooting for comparison reasons.

Today more shots of a cultivar flower, originating from the USA Prairie, a Black-eyed Susan - Rudbeckia hirta in reflected ultraviolet photography using my "work horse" UV filter, the Baader-U filter as well as in simulated bee and butterfly vision using my XBV filters. All shots were done at f11. Lens was a UV-Nikkor 105mm quartz fluorite lens. Light source was a modified Xenon flash. This was shot using another modified camera.

[click on image to see a larger one]

Human vision:

Reflected UV:

Simulated bee vision:

Simulated butterfly vision:

Quadriptych of human vision, UV, and simulated butterfly and bee vision (left to right, top to bottom):

Quadriptych in detail of human vision, UV, and simulated butterfly and bee vision (left to right, top to bottom):

This flower shows a very prominent UV bullseye pattern, as its petal tips are very UV bright (around 365nm) to about the middle and its center is very UV dark, and all this gets nicely visible also in simulated bee and butterfly vision. A matched set was shot using a newer camera system for comparison reasons HERE.

Saturday, July 8, 2017

Today detail shots of a cultivar flower, originating from the USA Prairie, a Black-eyed Susan - Rudbeckia hirta in reflected ultraviolet photography using my "work horse" UV filter, the Baader-U filter as well as in simulated bee vision using my XBV filter. All shots were done at f8. Lens was a UV-Nikkor 105mm quartz fluorite lens. Light source was sunlight.

[click on image to see a larger one]

Human vision:

Reflected UV:

Simulated bee vision:

Triptych of human vision, UV, and simulated bee vision (left to right, top to bottom):

This flower shows a very prominent UV bullseye pattern, as its petals are very UV bright (around 365nm) to about the middle and its center is very UV dark, and all this gets nicely visible also in simulated bee vision.

Today shots of a cultivar flower, originating from the USA Prairie, a Black-eyed Susan - Rudbeckia hirta in reflected ultraviolet photography using my "work horse" UV filter, the Baader-U filter as well as in simulated bee vision using my XBV filter. All shots were done at f8. Lens was a UV-Nikkor 105mm quartz fluorite lens. Light source was sunlight.

[click on image to see a larger one]

Human vision:

Reflected UV:

Simulated bee vision:

Triptych of human vision, UV, and simulated bee vision (left to right, top to bottom):

This flower shows a very prominent UV bullseye pattern, as its petals are very UV bright (around 365nm) to about the middle and its center is very UV dark, and all this gets nicely visible also in simulated bee vision.

Today shots of a current, long blooming flower, a yellowish white variant of a Treasury flower - Gazania rigens in reflected ultraviolet photography and simulated bee and butterfly vision. All shots were done at f8 in reflected ultraviolet photography using my "work horse" UV filter, the Baader-U filter, as well as my XBV filters for simulated bee and butterfly vision. Lens was a UV-Nikkor 105mm quartz fluorite lens. Light source was sunlight, background was the flower's own foliage.

[click on image to see a larger one]

Human vision:

Reflected UV:

Simulated bee vision:

Simulated butterfly vision:

Quadriptych of human vision, UV, and simulated butterfly and bee vision (left to right, top to bottom):

This Gazania's outer petals reflect strongly UV around 372nm, wheras the inner parts are much darker hence forming UV nectar guides for bees. There are also highly UV reflecting marks inside around a dark UV center, all invisible to us humans but clearly visible to bees, and all this gets nicely visible here, also in simulated bee vision.

Today shots of a current, long blooming flower, an all yellow variant of a Treasury flower - Gazania rigens in reflected ultraviolet photography and simulated bee vision. All shots were done at f8 in reflected ultraviolet photography using my "work horse" UV filter, the Baader-U filter, as well as my XBV filters for simulated bee vision. Lens was a UV-Nikkor 105mm quartz fluorite lens. Light source was sunlight, background was the flower's own foliage.

[click on image to see a larger one]

Human vision:

Reflected UV:

Simulated bee vision:

Triptych of human vision, UV, and simulated bee vision (left to right, top to bottom):

This Gazania's outer petals reflect strongly UV around 365nm, and there are also highly UV reflecting marks inside around a dark UV center, all invisible to us humans, but all this gets nicely visible, also in simulated bee vision.

The UV-Nikkor 105mm image is shown on the left side, the Coastal Optical Systems 105mm on the right side. First batch was shot at f4.5, second batch at f8. White balance was done for the UV-Nikkor 105mm.

The UV-Nikkor 105mm seems to have an edge over the Coastal Optics 105mm in terms of sharpness and contrast, especially when used fully open at f4.5, but stopped down to f8 the difference gets significantly smaller, as the Coastal gains quite a bit of sharpness and also contrast.

Both lenses require about the same white balance, due to their flat UV transmission (more about that later) and show about identical exposure, with exposure times having a slight nod towards the Coastal Optics lens (1/3 stop less), which in practice is insignificant.

Today about shooting with an UV lens (Coastal Optical Systems / Jenoptik UV-Micro-Apo f4 / 105mm) and considering how delicate those beasts can be to handle; here about using the right sunshade. Sounds rather boring actually, as we all rely on modern multicoated lenses and on my excursions I hardly ever see a photographer using his sunshade. But well, UV photography is a rather tricky subject anyway, and all aspects need consideration...

[click on image to see a larger one]

These are first normal visible light images, second reflected UV images and as one clearly sees here, using a sunshade (right side) can be rather critical, as the left image proves, showing very low contrast. In my case here, I used an 80mm deep shade for maximum effect, but w/o causing vignetting.

Friday, June 30, 2017

Today a spectrometric test using that previously mentioned Petri Kuribayashi f3.5/35mm lens, compared to a recently found Kyoei E-Acall f3.5/50mm enlarger lens, as a proof that both actually have a very useful lens transmission, especially in UV.

[click on image to see a larger one]

The Kuribayashi 35mm still reaches deep into UV, even a bit below 320nm and shows a rather high UV at 365nm transmission of over 80%. However the Kyoei E-Acall f3.5/50mm enlarger lens seems to be quite similar, reaches beyond 320nm too and has a tad above 70% UV transmission at 365nm, so another useful addition to the rather short list of UV capable lenses. It has a different blueish coating, compared to the golden coating the 35mm Kuri has, hence suppressing a bit the blue and UV area.

I will test how it performs as a UV taking lens soon, time permitting.

Monday, June 12, 2017

Today a spectrometric test of materials used for white balancing of reflected UV photography: SPECTRALON (R) calibrated reflection standard made and sold by company LABSPHERE, sintered porous PTFE (porous filter discs, as used in filters for chemical processes and medicine) and virgin white PTFE (white extruded industrial material for various purposes sold as plates, cut discs etc.) to see which of these materials would be suitable for the UV-VIS range of 300 - 700nm. Many years ago I had proposed to use virgin white Teflon (R) / PTFE as a cheap and easy to get material.

[click on image to see a larger one]

The 100% (green, hard to see) line is the reflection of the SPECTRALON (R) reflection standart as sold by LABSPHERE and is used as a refence. The yellow line indicates the reflection of some seemingly sintered PTFE, now sold as white balance filter mounted into filters rings (52mm in this case), originally made and sold as 50mm porous filter material for chemical and medical purposes. This latter material reflects rather evenly between 80-83%. The virgin PTFE in comparision has a more uneven reflection of 72-75% (>320nm), down to 68% below 320nm. For amateur photographic purposes the two cheaper materials provide sufficient evenness, with an edge in favour of the sintered PTFE. For professional applications, both are however no alternative to the industry standard SPECTRALON (R) which shows outstanding evenness.

Remark: all such materials are extremely sensitive to dirt, fingerprints etc. which reduces the UV reflection massively, so have to be kept clean at all times and need to be cleaned asap if so contaminated. Best to clean is to brush with purified water, a detergent and ethanol, then rinse with purified water, then let dry in a dust and lint free environment or dry with pressured clean air.

Monday, May 8, 2017

Today a spectrometric test using that previously mentioned Petri Kuribayashi f3.5/35mm lens, compared to a Kyoei Acall f3.5/80mm lens in M44 thread mount, as a proof that both actually have a very useful lens transmission, especially in UV.

[click on image to see a larger one]

The Kuribayashi 35mm still reaches deeper into UV, even a bit below 320nm and shows a rather high UV at 365nm transmission of over 80%. However the Kyoei Acall f3.5/80mm short tele lens seems to be quite similar, reaches beyond 340nm and has a 70% UV transmission at 365nm, just 10% lower!

Thursday, April 6, 2017

Today a spectrometric test using that previously mentioned Petri Kuribayashi f3.5/35mm lens, compared to a Kyoei Acall f3.5/180mm lens in M42 thread mount, as a proof that both actually have a very different lens transmission, especially in UV.

[click on image to see a larger one]

The Kuribayashi 35mm reaches much deeper into UV, even a bit below 320nm and shows a rather high UV at 365nm transmission of over 80%. However the Kyoei Acall f3.5/180mm tele lens seems to be a very different beast, as it has no useful at all UV transmission!

Today a spectrometric test using that previously mentioned Petri Kuribayashi f3.5/35mm lens, compared to the W. Acall f3.5/35mm lens in Leica Thread Mount (LTM), as a proof that both actually have a very different lens transmission, especially in UV.

[click on image to see a larger one]

The Kuribayashi 35mm reaches much deeper into UV, even a bit below 320nm and shows a rather high UV at 365nm transmission of over 80%. However the similar looking W. Acall 35mm seems to be a very different beast, as it has at 365nm only approx 5% UV transmission, so basically none useful at all!

Tuesday, January 17, 2017

Gasometer Oberhausen Museum has reported a record breaking visitor count of 750.000 by end of 2016 for their "Wonders of Nature" exhibit and has hence decided to extend until November 30, 2017. I have participated in that with some of my works in large prints and a video presentation. An impressive location it is, the highest Museum in Germany (116m high, 66m wide) showing some amazing exhibit areas inside:

(C) Gasometer Oberhausen

My contribution are some images of a Zinnia haageana flower in large prints, on display in their exhibition area below that 20 meter large earth globe, demonstrating the difference between our human vision, as well as a video presentation shown on LCD panel which originates from the BBC series "How to grow a planet - The hidden World of UV" which has several of my VIS and UV images of different flowers in it.

The exhibit shows in total some 150 large images and video presentations by the most famous nature photographers and is not only visually stunning, but also highly educative and suited for interested individuals as well as families and schools. Go have a look, it will be well worth it!

There is still a printed book available about it: Wunder der Natur, Die Intelligenz der Schöpfung ISBN/EAN: 9783837514629 (in German language)

About Me

This is my blog about my film and photographic work in 3D, ultraviolet UV, infrared IR and fluorescence using special lenses and equipment. All text and images carry my copyright and I do not allow to link to or copy / download from my site or any parts thereof without my prior permission.
email me in case of questions or interest in my images (esp. for non-profit orgs) or if you need a complete camera + lens + filter + light set for UV photography:
postmaster AT macrolenses.de